Date: Sat, 29 Mar 1997 12:20:33 -0800 From: Amancio Hasty <hasty@rah.star-gate.com> To: Richard Tobin <richard@cogsci.ed.ac.uk> Cc: Steve Passe <smp@csn.net>, multimedia@freebsd.org Subject: Re: newest bt848 driver Message-ID: <199703292020.MAA10154@rah.star-gate.com> In-Reply-To: Your message of "Sat, 29 Mar 1997 15:12:10 GMT." <27837.199703291512@pitcairn.cogsci.ed.ac.uk>
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>From The Desk Of Richard Tobin :
> #define DMA_PROG_ALLOC 8
> ...
> bktr->dma_prog = get_bktr_mem(unit, DMA_PROG_ALLOC);
>
> This appears to be allocating only 8 bytes for the DMA program???
>
> -- Richard
>
get_bktr_mem allocates memory in terms of pages (4096 bytes)
static vm_offset_t
get_bktr_mem( int unit, unsigned size )
{
vm_offset_t addr = 0;
addr = vm_page_alloc_contig(size, 0x100000, 0xffffffff, 1<<24);
if (addr == 0)
addr = vm_page_alloc_contig(size, 0x100000, 0xffffffff,
PAGE_SIZE);
if (addr == 0) {
printf("meteor%d: Unable to allocate %d bytes of memory.\n",
unit, size);
}
return addr;
}
in /sys/vm/vm_page.c:
vm_offset_t
vm_page_alloc_contig(size, low, high, alignment)
vm_offset_t size;
vm_offset_t low;
vm_offset_t high;
vm_offset_t alignment;
{
return ((vm_offset_t)contigmalloc(size, M_DEVBUF, M_NOWAIT, low, high,
alignment, 0ul));
}
Have fun,
Amancio
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